The news came as shock to a host of Singaporean media and chefs from around the world, including chefs Guy Savoy and Daniel Boulud, who were at the Marina Bay Sands for a press event. The chefs also have restaurants in the resort complex.

The hotel press event kicked off around 5 p.m., with all the chefs, including Mr. Santamaria.

“We were told that Santi suffered a heart attack around 8 p.m. in his restaurant’s kitchen,” says a friend of the chef who was at the event. “He was carried out on a stretcher, and then word came that he had passed away in the ambulance.”

Raymong Lim, marketing manager for Singapore Les Amis Group, said, “Despite his fame, chef Santi was a down-to-earth man.” Mr. Lim, who knew the chef for three years, and Mr. Santamaria were scheduled to have lunch today and were still exchanging emails yesterday on where to go. “His passing is a great loss for both the Catalan and the international food scene.”

Mr. Santamaria, whose Barcelona Restaurant Can Fabes has three Michelin stars, may be best known as the chef who spoke out against molecular gastronomy, the cooking style popularized by fellow Catalan chef Ferran Adrià, owner of El Bulli in Spain. Mr. Santamaria preferred to use natural ingredients and traditional cooking techniques. He opened his Singapore restaurant in May 2010, and recently received the Best New Restaurant Award in Singapore Tatler’s Best Restaurant Guide for 2011. His daughter, Regina Santamaria, is working in Santi in Singapore with some members of his team who relocated from Spain.